public class Example4_5 {
  public static void main(String args[]) {
    Rect ractangle = new Rect();
    ractangle.width = 109.87;
    ractangle.height = 25.18;
    double area = ractangle.getArea();
    System.out.println("矩形的面积:"+area);
    Lader lader = new Lader();
    lader.above = 10.798;
    lader.bottom = 156.65;
    lader.height = 18.12;
    area = lader.getArea();
    System.out.println("梯形的面积："+area);
  }
}
